Preoperative assessment of the individual anatomy of the superior petrosal vein complex using balanced fast field echo magnetic resonance imaging.

BACKGROUND: Here, we sought to examine the validity and reproducibility of balanced fast field echo (bFFE) for assessing superior petrosal vein (SPV) complex (SPVC) anatomy. METHODS: Preoperative bFFE or equivalent scans and operative videos were studied and directly compared with regard to the individual anatomical features of SPVCs and their relation to the operative field. The anatomical details of the bFFE findings of the non-operated side (group 2) of all 50 patients were then reviewed, including the presence of petrosal-galenic anastomosis, and finally compared to the operated SPVCs (group 1). RESULTS: A complete correlation between bFFE and intraoperative findings was observed in 62% of cases and had a significant correlation with 3 Tesla magnet strength and higher pixel bandwidth (rbis = - 0.47; p = 0.005). The sensitivity and specificity of bFFE magnetic resonance imaging were 93.7 and 95.2%, respectively, for detecting an SPV disturbing the operative field, and 97.3% and 95% for a disturbing tributary, respectively. Each group had 50 SPVCs, with a total of 70 and 64 SPVs, 10 and 11 general SPVC configurations, as well as 29 and 28 different individual anatomical variations in groups 1 and 2, respectively. Both groups had 1-3 SPVs with a similar distribution of frequencies [Chi-square (4) = 27.56; p = 0.0145 (Fisher's exact test)]. The similarity of the general configurations was not statistically significant. The same four predominant configurations constituted 80% of the SPVCs in each group. The vein of the cerebellopontine fissure was most frequently found in 86% and 88% of cases, and a petrosal-galenic anastomosis was seen in 38% and 40% of groups 1 and 2, respectively. CONCLUSIONS: Individual SPVC variations are extensive. Good quality bFFE or equivalents are feasible for preoperative SPVC assessments. However, methods improving vascular visualization are recommended.

Non-contrast assessment of blood-brain barrier permeability to water in mice: An arterial spin labeling study at cerebral veins.

Blood-brain barrier (BBB) plays a critical role in protecting the brain from toxins and pathogens. However, in vivo tools to assess BBB permeability are scarce and often require the use of exogenous contrast agents. In this study, we aimed to develop a non-contrast arterial-spin-labeling (ASL) based MRI technique to estimate BBB permeability to water in mice. By determining the relative fraction of labeled water spins that were exchanged into the brain tissue as opposed to those that remained in the cerebral veins, we estimated indices of global BBB permeability to water including water extraction fraction (E) and permeability surface-area product (PS). First, using multiple post-labeling delay ASL experiments, we estimated the bolus arrival time (BAT) of the labeled spins to reach the great vein of Galen (VG) to be 691.2 ± 14.5 ms (N = 5). Next, we investigated the dependence of the VG ASL signal on labeling duration and identified an optimal imaging protocol with a labeling duration of 1200 ms and a PLD of 100 ms. Quantitative E and PS values in wild-type mice were found to be 59.9 ± 3.2% and 260.9 ± 18.9 ml/100 g/min, respectively. In contrast, mice with Huntington's disease (HD) revealed a significantly higher E (69.7 ± 2.4%, P = 0.026) and PS (318.1 ± 17.1 ml/100 g/min, P = 0.040), suggesting BBB breakdown in this mouse model. Reproducibility studies revealed a coefficient-of-variation (CoV) of 4.9 ± 1.7% and 6.1 ± 1.2% for E and PS, respectively. The proposed method may open new avenues for preclinical research on pathophysiological mechanisms of brain diseases and therapeutic trials in animal models.

MRI assessment of cerebral oxygen extraction fraction in the medial temporal lobe.

The medial temporal lobe (MTL) is a key area implicated in many brain diseases, such as Alzheimer's disease. As a functional biomarker, the oxygen extraction fraction (OEF) of MTL may be more sensitive than structural atrophy of MTL, especially at the early stages of diseases. However, there is a lack of non-invasive techniques to measure MTL-OEF in humans. The goal of this work is to develop an MRI technique to assess MTL-OEF in a clinically practical time without using contrast agents. The proposed method measures venous oxygenation (Yv) in the basal veins of Rosenthal (BVs), which are the major draining veins of the MTL. MTL-OEF can then be estimated as the arterio-venous difference in oxygenation. We developed an MRI sequence, dubbed arterial-suppressed accelerated T2-relaxation-under-phase-contrast (AS-aTRUPC), to quantify the blood T2 of the BVs, which was then converted to Yv through a well-established calibration model. MTL-OEF was calculated as (Ya-Yv)/Ya × 100%, where Ya was the arterial oxygenation. The feasibility of AS-aTRUPC to quantify MTL-OEF was evaluated in 16 healthy adults. The sensitivity of AS-aTRUPC in detecting OEF changes was assessed by a caffeine ingestion (200 mg) challenge. For comparison, T2-relaxation-under-spin-tagging (TRUST) MRI, which is a widely used global OEF technique, was also acquired. The dependence of MTL-OEF on age was examined by including another seven healthy elderly subjects. The results showed that in healthy adults, MTL-OEF of the left and right hemispheres were correlated (P=0.005). MTL-OEF was measured to be 23.9±3.6% (mean±standard deviation) and was significantly lower (P<0.0001) than the OEF of 33.3±2.9% measured in superior sagittal sinus (SSS). After caffeine ingestion, there was an absolute percentage increase of 9.1±4.0% in MTL-OEF. Additionally, OEF in SSS measured with AS-aTRUPC showed a strong correlation with TRUST OEF (intra-class correlation coefficient=0.94 with 95% confidence interval [0.91, 0.96]), with no significant bias (P=0.12). MTL-OEF was found to increase with age (MTL-OEF=20.997+0.100 × age; P=0.02). In conclusion, AS-aTRUPC MRI provides non-invasive assessments of MTL-OEF and may facilitate future clinical applications of MTL-OEF as a disease biomarker.

Assessment of Cerebral Circulatory Arrest via CT Angiography and CT Perfusion in Brain Death Confirmation.

OBJECTIVE: To compare the utility of computed tomography perfusion (CTP) and three different 4-point scoring systems in computed tomography angiography (CTA) in confirming brain death (BD) in patients with and without skull defects. MATERIALS AND METHODS: Ninety-two patients clinically diagnosed as BD using CTA and/or CTP for confirmation were retrospectively reviewed. For the final analysis, 86 patients were included in this study. Images were re-evaluated by three radiologists according to the 4-point scoring systems that consider the vessel opacification on 1) the venous phase for both M4 segments of the middle cerebral arteries (MCAs-M4) and internal cerebral veins (ICVs) (A60-V60), 2) the arterial phase for the MCA-M4 and venous phase for the ICVs (A20-V60), 3) the venous phase for the ICVs and superior petrosal veins (ICV-SPV). The CTP images were independently reviewed. The presence of an open skull defect and stasis filling was noted. RESULTS: Sensitivities of the ICV-SPV, A20-V60, A60-V60 scoring systems, and CTP in the diagnosis of BD were 89.5%, 82.6%, 67.4%, and 93.3%, respectively. The sensitivity of A20-V60 scoring was higher than that of A60-V60 in BD patients (p < 0.001). CTP was found to be the most sensitive method (86.5%) in patients with open skull defect (p = 0.019). Interobserver agreement was excellent in the diagnosis of BD, in assessing A20-V60, A60-V60, ICV-SPV, CTP, and good in stasis filling (κ: 0.84, 0.83, 0.83, 0.83, and 0.67, respectively). CONCLUSION: The sensitivity of CTA confirming brain death differs between various proposed 4-point scoring systems. Although the ICV-SPV is the most sensitive, evaluation of the SPV is challenging. Adding CTP to the routine BD CTA protocol, especially in cases with open skull defect, could increase sensitivity as a useful adjunct.

Optimization of 3D phase contrast venography for the assessment of the cranio-cervical venous system at 1.5 T.

PURPOSE: The aim of this work was to optimize a three-dimensional (3D) phase-contrast venography (PCV) product MR pulse sequence in order to obtain clinically reliable images with less artifacts for an improved depiction of the cranio-cervical venous vessels. METHODS: Starting from the product sequence, the 3D PCV protocol was optimized in eight steps with respect to the velocity encoding (Venc) direction and value, slice thickness, reduction of susceptibility artifacts and arterial contamination, gradient mode and radio-frequency (RF)-spoiling, B0-Shimming, asymmetric echo technique and RF-pulse type, and flip angle. The product and optimized protocol was used to perform 3D PCV in 12 healthy male volunteers with a median age of 50 years using a state-of-the-art 1.5-T MR system. For evaluation, the cranio-cervical venous system was divided into 15 segments. These segments were evaluated by three radiologists with experience in neuroradiology. An ordinal scoring system was used to access the overall diagnostic quality, arterial contamination, and the quality of visualization. RESULTS: Image quality in the optimized 3D PCV was graded as "excellent" by all readers in 65.3% of the cases (p < 0.0001). The visualization of venous segments was strongly improved: it was considered diagnostic in 81.8% of all cases using the optimized sequence and in 47.6% for the product 3D PCV (p < 0.0001), respectively. The optimized protocol improved the imaging of all venous segments (p < 0.0001). CONCLUSION: The optimized 3D PCV pulse sequence showed superior results compared to the product 3D PCV for the visualization and evaluation of the venous system in all healthy volunteers.

Assessment of Hemodynamic Alterations in Cerebral Veins in Patients With Intracerebral Hemorrhage Using Duplex Color-Coded Sonography.

OBJECTIVES: To investigate the contributions of hemodynamic alterations in cerebral veins to the prognosis of patients with primary intracerebral hemorrhage (ICH). METHODS: Duplex color-coded sonography was performed on 87 ICH patients between July 2016 and October 2017. The time-averaged peak velocity, the time-averaged mean velocity (TAMV), the blood flow volume (BFV) of bilateral internal jugular veins (IJVs) and vertebral veins (VVs), and the mean velocities of bilateral basal veins of Rosenthal, straight sinus, and bilateral transverse sinuses were calculated to understand the relationship of hemodynamic data with prognosis in patients with ICH. RESULTS: The study revealed that the time-averaged peak velocities, TAMVs and BFVs of both right IJV and VV in ICH patients with good clinical outcomes were higher than those of the left IJV and VV, whereas statistically significant differences were not found in the mean velocity of bilateral veins of Rosenthal. The perihematomal edema volume, time-averaged peak velocities, TAMVs, and BFVs of the bilateral IJVs and right VV and the TAMV of the left VV were associated with the prognosis of ICH patients in the univariate analysis. However, the TAMV of the right IJV and BFV of the left IJV were the independent factors that predicted prognosis in multivariate analysis. Partial correlation showed that there was a linear dependence between the differences in TAMV and BFV between bilateral IJVs. CONCLUSIONS: The presence of hemodynamic changes in cerebral veins in patients with ICH has an impact on prognosis.

Dynamic assessment of venous anatomy and function in neurosurgery with real-time intraoperative multimodal ultrasound: technical note.

The relevance of the cerebral venous system is often underestimated during neurosurgical procedures. Damage to this draining system can have catastrophic implications for the patient. Surgical decision-making and planning must consider each component of the venous compartment, from the medullary draining vein to the dural sinuses and extracranial veins. Intraoperative ultrasound (ioUS) permits the real-time study of venous compartments using different modalities, thus allowing complete characterization of their anatomical and functional features. The B-mode (brightness mode) offers a high-resolution anatomical representation of veins and their relationships with lesions. Doppler modalities (color, power, spectral) allow the study of blood flow and identification of vessels to distinguish their functional characteristics. Contrast-enhanced US allows one to perform real-time angiosonography showing both the functional and the anatomical aspects of vessels. In this technical report, the authors demonstrate the different applications of multimodal ioUS in neurosurgery for identifying the anatomical and functional characteristics of the venous compartment. They discuss the general principles and technical nuances of ioUS and analyze their potential implications for the study of various venous districts during neurosurgical procedures.

Non-invasive Intracranial Pressure Assessment in Brain Injured Patients Using Ultrasound-Based Methods.

BACKGROUND: Non-invasive measurement of intracranial pressure (ICP) can be invaluable in the management of critically ill patients. Invasive measurement of ICP remains the "gold standard" and should be performed when clinical indications are met, but it is invasive and brings some risks. In this project, we aim to validate the non-invasive ICP (nICP) assessment models based on arterious and venous transcranial Doppler ultrasonography (TCD) and optic nerve sheath diameter (ONSD). METHODS: We included brain injured patients requiring invasive ICP monitoring (intraparenchymal or intraventricular). We assessed the concordance between ICP measured non-invasively with arterious [flow velocity diastolic formula (ICPFVd) and pulsatility index (PI)], venous TCD (vPI) and ICP derived from ONSD (nICPONSD) compared to invasive ICP measurement. RESULTS: Linear regression showed a positive relationship between nICP and ICP for all the methods, except PIv. ICPONSD showed the strongest correlation with invasive ICP (r = 0.61) compared to the other methods (ICPFVd, r = 0.26, p value = 0.0015; PI, r = 0.19, p value = 0.02, vPI, r = 0.056, p value = 0.510). The ability to predict intracranial hypertension was highest for ICPONSD (AUC = 0.91; 95% CI, 0.85-0.97 at ICP > 20 mmHg), with a sensitivity and specificity of 85%, followed by ICPFVd (AUC = 0.67; 95% CI, 0.54-0.79). CONCLUSIONS: Our results demonstrate that among the non-invasive methods studied, ONSD showed the best accuracy in the detection of ICP.

Longitudinal Volume Quantification of Deep Medullary Veins in Patients with Cerebral Venous Sinus Thrombosis : Venous Volume Assessment in Cerebral Venous Sinus Thrombosis Using SWI.

PURPOSE: Susceptibility-weighted imaging (SWI) visualizes small cerebral veins with high sensitivity and could, thus, enable quantification of hemodynamics of deep medullary veins. We aimed to evaluate volume changes of deep medullary veins in patients with acute cerebral venous sinus thrombosis (CVST) over time in comparison to healthy controls. METHODS: All magnetic resonance imaging (MRI) experiments were executed at 3 T using a 32-channel head coil. Based on SWI and semiautomatic postprocessing (statistical parametric mapping [SPM8] and ANTs), the volume of deep medullary veins was quantified in 14 patients with acute CVST at baseline and the 6­month follow-up, as well as in 13 healthy controls undergoing repeated MRI examination with an interscan interval of at least 1 month. RESULTS: Deep medullary venous volume change over time was significantly different between healthy controls and patient groups (p < 0.001). Patients with superior sagittal sinus thrombosis (SSST) showed a significant decline from baseline to follow-up measurements (9.8 ± 4.9 ml versus 7.5 ± 4.2 ml; p = 0.02), whereas in patients with transverse sinus thrombosis (TST) and healthy controls no significant volume changes were observable. CONCLUSIONS: Venous volume quantification was feasible and reproducible both in healthy volunteers and in patients. The decrease of venous volume in patients over time represents improvement of venous drainage, reduction of congestion, and normalization of microcirculation due to treatment. Thus, quantification of venous microcirculation could be valuable for estimation of prognosis and guidance of CVST therapy in the future.

Assessment and Treatment of Peritumoral Cortical Veins in Parasagittal Meningiomas with Application of 3-Dimensional Imaging Fusion Model.

BACKGROUND: Operation of cortical veins is the keystone of parasagittal meningioma (PSM) resection. Little is known about pathologic changes of the veins and proper treatment. We built 3-dimensional (3D) image fusion models by neuronavigation to analyze the features of peritumoral cortical veins for PSMs and explore intraoperative treatment options. METHODS: We performed a prospective study of 42 consecutive surgically treated PSM patients who underwent preoperative evaluation of peritumoral cortical veins using a 3D venous-tumor fusion model established by a neuronavigation system. We categorized cortical veins into 3 types: single-end anastomosis (type a), tumor-to-end anastomosis (type b), and end-to-end anastomosis (type c). We present surgical strategies to operate these veins. RESULTS: Preoperative evaluation demonstrated 39 patients with peritumoral cortical veins. The 3D models show 100% of the veins (95 in total), which were confirmed intraoperation. The postoperative complication rates after vein injury were 60% (type a), 16.7% (type c), and 0% (type b). Ten patients (23.8%) had residual tumor because of venous protection (equal to Simpson grade III). After correlation analysis, type b and c cortical veins were positively correlated with tumor volume. CONCLUSIONS: The anastomoses of cortical veins may provide compensation for venous transaction. There may be a time-evolution relationship between different cortical veins (type a to c to b). Treatment of cortical veins should follow the following principles: single-end veins must be protected, tumor-to-end veins should be transacted directly, and end-to-end veins could be cut selectivity based on the degree of occlusion of the superior sagittal sinus. Detailed preoperative assessment of peritumoral cortical veins is critical for proper treatment.

4D flow MRI for intracranial hemodynamics assessment in Alzheimer's disease.

Cerebral blood flow, arterial pulsation, and vasomotion play important roles in the transport of waste metabolites out of the brain. Impaired vasomotion results in reduced driving force for the perivascular/glymphatic clearance of beta-amyloid. Noninvasive cerebrovascular characteristic features that potentially assess these transport mechanisms are mean blood flow (MBF) and pulsatility index (PI). In this study, 4D flow MRI was used to measure intra-cranial flow features, particularly MBF, PI, resistive index (RI) and cross-sectional area in patients with Alzheimer's disease (AD), mild cognitive impairment and in age matched and younger cognitively healthy controls. Three-hundred fourteen subjects participated in this study. Volumetric, time-resolved phase contrast (PC) MRI data were used to quantify hemodynamic parameters from 11 vessel segments. Anatomical variants of the Circle of Willis were also cataloged. The AD population reported a statistically significant decrease in MBF and cross-sectional area, and also an increase in PI and RI compared to age matched cognitively healthy control subjects. The 4D flow MRI technique used in this study provides quantitative measurements of intracranial vessel geometry and the velocity of flow. Cerebrovascular characteristics features of vascular health such as pulsatility index can be extracted from the 4D flow MRI data.

Angiographic assessment of variants of basal vein of Rosenthal in idiopathic subarachnoid hemorrhage.

Previous studies have reported the possible contribution of a primitive variant of the basal vein of Rosenthal (BVR) in the cause of idiopathic subarachnoid hemorrhage (ISAH). The purpose of this study was to assess the drainage patterns of the BVR among ISAH patients. The venous phase at cerebral angiography was retrospectively analyzed in 19 patients with ISAH and then compared with patients with unruptured aneurysms as controls. A relationship was found between ISAH and the presence of a primitive variant. However, the venous configuration effect on bleeding is still unknown.

Catheter venography for the assessment of internal jugular veins and azygous vein: position statement by expert panel of the International Society for Neurovascular Disease.

This document by an expert panel of the International Society for Neurovascular Disease is aimed at presenting current technique and interpretation of catheter venography of the internal jugular veins, azygous vein and other veins draining the central nervous system. Although interventionalists agree on general rules, significant differences exist in terms of details of venographic technique and interpretations of angiographic pictures. It is also suggested that debatable findings should be investigated using multimodal diagnostics. Finally, the authors recommend that any publication on chronic cerebrospinal venous insufficiency should include detailed description of venographic technique used, to facilitate a comparison of published results in this area.

Assessment of cerebral venous return by a novel plethysmography method.

BACKGROUND: Magnetic resonance imaging and echo color Doppler (ECD) scan techniques do not accurately assess the cerebral venous return. This generated considerable scientific controversy linked with the diagnosis of a vascular syndrome known as chronic cerebrospinal venous insufficiency (CCSVI) characterized by restricted venous outflow from the brain. The purpose of this study was to assess the cerebral venous return in relation to the change in position by means of a novel cervical plethysmography method. METHODS: This was a single-center, cross-sectional, blinded case-control study conducted at the Vascular Diseases Center, University of Ferrara, Italy. The study involved 40 healthy controls (HCs; 18 women and 22 men) with a mean age of 41.5 ± 14.4 years, and 44 patients with multiple sclerosis (MS; 25 women and 19 men) with a mean age of 41.0 ± 12.1 years. All participants were previously scanned using ECD sonography, and further subset in HC (CCSVI negative at ECD) and CCSVI groups. Subjects blindly underwent cervical plethysmography, tipping them from the upright (90°) to supine position (0°) in a chair. Once the blood volume stabilized, they were returned to the upright position, allowing blood to drain from the neck. We measured venous volume (VV), filling time (FT), filling gradient (FG) required to achieve 90% of VV, residual volume (RV), emptying time (ET), and emptying gradient (EG) required to achieve 90% of emptying volume (EV) where EV = VV - RV, also analyzing the considered parameters by receiver operating characteristic (ROC) curves and principal component mathematical analysis. RESULTS: The rate at which venous blood discharged in the vertical position (EG) was significantly faster in the controls (2.73 mL/second ± 1.63) compared with the patients with CCSVI (1.73 mL/second ± 0.94; P = .001). In addition, respectively, in controls and in patients with CCSVI, the following parameters were highly significantly different: FT 5.81 ± 1.99 seconds vs 4.45 ± 2.16 seconds (P = .003); FG 0.92 ± 0.45 mL/second vs 1.50 ± 0.85 mL/second (P < .001); RV 0.54 ± 1.31 mL vs 1.37 ± 1.34 mL (P = .005); ET 1.84 ± 0.54 seconds vs 2.66 ± 0.95 seconds (P < .001). Mathematical analysis demonstrated a higher variability of the dynamic process of cerebral venous return in CCSVI. Finally, ROC analysis demonstrated a good sensitivity of the proposed test with a percent concordant 83.8, discordant 16.0, tied 0.2 (C = 0.839). CONCLUSIONS: Cerebral venous return characteristics of the patients with CCSVI were markedly different from those of the controls. In addition, our results suggest that cervical plethysmography has great potential as an inexpensive screening device and as a postoperative monitoring tool.

Contemporary angiographic assessment and clinical implications of the vein of labbé in neurotologic surgery.

BACKGROUND: To better understand the drainage patterns of the 3 largest superficial anastomotic veins (SAVs), namely, vein of Labbé (VL), the vein of Trolard (VT), and the superficial sylvian vein (SSV). To assess the dominance of the VL in the superficial cortical venous system, because this vein may be encountered in neurotologic surgery and its interruption may result in a venous infarct of the temporal lobe. METHODS: The database of the radiology department at the University of Cincinnati was used to identify all patients who underwent a diagnostic angiographic study between September 1, 2009, and January 1, 2010. Studies were excluded if there were intracranial masses or vascular lesions. Angiograms were assessed for the presence of the VL, VT, and SSV, as well as vessel dominance, determined by their relative calibers. RESULTS: A total of 101 patients (81%) underwent bilateral and 48 unilateral angiography, for a total of 250 studies. Mean age was 55 years (range, 16-83 yr). Seventy-seven patients (53%) were females. The most common pattern observed was the presence of all 3 SAVs (78%). The VL was absent or poorly developed in 34 studies (14%) and was the dominant superficial vein in 51 (20%), of which 28 (55%) occurred on the right. CONCLUSION: Considerable variability is demonstrated in the drainage patterns of the SAVs. Care should be taken in neurotologic surgery to avoid injuring the VL because this may represent the single dominant drainage pathway of the lateral surface of the temporal lobe in a large number of patients.

Assessment of the cerebral venous system from the transcondylar ultrasound window using virtual navigator technology and MRI.

The Chronic Cerebro-Spinal Venous Insufficiency, recently described as a possible role in Multiple Sclerosis pathogenesis, is diagnosed and classified with Echo Color Doppler (ECD) examination of the extra- and intra-cranial veins. As to the intracranial examination, the presence of reflux in the deep cerebral veins (DCVs) or in the dural sinuses is inspected, with a new insonation approach, i.e. the transcondylar window. This work describes a procedure for the co-registration of anatomical Proton Density-weighted Magnetic Resonance Images (MRI) with the intracranial ECD obtained through the transcondylar window. The procedure, preliminarily tested on 10 volunteers, allowed to assess what are the DCVs visible from this new insonation approach and their position relative to the surrounding brain tissues.

The value of cerebral Doppler venous haemodynamics in the assessment of multiple sclerosis.

Iron stores in the white and deep grey matter in course of multiple sclerosis (MS) have never been explained and could be related to abnormalities in venous drainage, but this possibility has never before been investigated. From an initial cohort of 320 subjects, after application of exclusion criteria, we selected 109 patients affected by MS, and 177 controls respectively composed by age- and sex-matched, healthy aged, and patients affected by other neurological diseases. They blindly underwent transcranial and extracranial Color-Doppler sonographic examination (TCCS-ECD), aimed at investigating five parameters related to normal cerebral venous outflow haemodynamics. Overall we analyzed 1430 TCSS-ECD parameters. In controls we found 861 normal parameters of cerebral venous return vs. 24 anomalous, whereas in MS 288 parameters were normal and 257 anomalous, respectively. Consequently, each of the considered Doppler haemodynamic parameters, when compared to revised McDonald criteria as a gold standard of MS diagnosis, showed separately a highly significant sensitivity and a noteworthy specificity. However, the detection >or=2 parameters in the same subject, never observed in controls, perfectly overlapped the diagnosis of MS (value, 95%CI: sensitivity 100%, 97-100; specificity 100%, 98-100; positive predictive value 100%, 97-100, negative predictive value 100%, 98-100; p<0.0001). Moreover, this study demonstrates a significant impairment of cerebral venous drainage in patients affected by MS, a mechanism potentially related to increased iron stores.

Serial ultrasound assessment of the basal vein of Rosenthal in HSV encephalitis.

Herpes simplex virus encephalitis (HSVE) typically affects the baso-temporal brain. The venous blood drainage of this region mainly occurs via the basal vein of Rosenthal (BVR), which can easily be monitored by transcranial color-coded duplex sonography (TCCS), and might be a useful parameter for the activity of the disease. Serial blood flow velocity (BFV) measurements of the BVR and the basal cerebral arteries were performed in five acute HSVE patients by means of transcranial color-coded duplex sonography (TCCS). Remarkable increased BFV of the BVR at the affected side was found in all patients, showing a maximum within the first 8 d of infection followed by a tendency toward normalisation during the next weeks. In comparison, changes of BFV in the basal cerebral arteries were much more heterogeneous. Our findings suggest that TCCS measurements of the BVR might be used as an additional diagnostic bed-side tool to evaluate patients with HSVE during the acute stage.